I needed someone to deliver things in the neighborhood. I called a jewish company who sent me one of the non-jewish delivery men they use for deliveries. Can I now contact the non-jewish delivery man directly for the next job I have, to avoid giving the jewish company that was the middleman their extra fee?
I don’t know of any formal prohibition if you used them on a one time basis and didn’t say anything about the future and they didn’t stipulate any conditions. Nevertheless, it may be bad middos-using information you got from someone in a way that is detrimental to him.